Expanded load bearing member and method of forming the same



Dec. 5, 1933. KESSLER 1,937}762 EXPANDED LOAD BEARING MEMBER AND METHOD OF FORMING THE SAME Filed Feb. 27, 1931 Heavy (Z. (388191 Patented Dec. 5, 1933 l EXPANDED LoAD BEARING MEMBER AND METHOD or FORMING THE SAME Harry A. Kessler, Chicago, 111., assignor to Kalman Steel Company, Inc., Chicago, 111., a corporation of Delaware Application February 27, 1931. Serial No,518,674

6 Claims. (Cl- 164-65) r This invention relates to the manufacture of metallic load bearing members of the type produced from a single blank and which are characterized by trussed body portions and integral end supporting extensions of beam-like form and the invention is concernedgenerally in improvements in such a load bearing member, in the method of producing it and in the blank from which it is'formed.

In the production of a load bearing member of the type generally described by a continuous method the end supportingextensions are provided by bending the terminal portions of the lower flange or chord toward the terminal portionsoi" the upper flange or chord and uniting the two for a suitable distance as by welding or other forms of connection. Heretofore, it has been the practice in the operations preceding the formation of the end supporting extensions to first slit the web of the blank from which the member is to be formed throughout its entire extent in the manner in which diamond mesh lath, so-called, is slit, that is to say, with the slits of each row in staggered or break-joint relation to theslits of the adjacent row or rows. The slitting of the blank in this manner requires, prior to the joining of the terminal portions of the chords to form the supporting extensions, the cutting away of lattice work at theends oi the trussed portions and these operations have added to the labor and cost of manufacture in additionto involving waste of material.

The principal object ofthe present'invention is to overcome the above disadvantages, that is to say, to produce a load'bearing member having an expanded trussed body portion and integral end supporting extensions without the necessity of cutting away of the. lattice work. after the expansion of the trussed body portion. With this object in view, the invention consists generally in cutting away at the terminal portions of the blank, prior to the slitting and expanding operations, those portionsof the web which heretofore have been cut away after these operations and spreading the terminal portions of the flanges onchordsto increase the width of the slots formed in this manner to enable passage of the blank between the rollswhich are to slit the body portion of the web without slitting of the web portions at the sides of the slots which are ultimately to form the solid web of the end supporting: extensions. The blank is then expanded andJ the terminal portions of the chords may be operated upon to form the end supportingextensions, in the desired manner.

Advantages obtained by the invention are: (1), waste of material is eliminated; (2), the ultimate width of the web of the solid supporting extension is independent of the arrangement of the slits in the web of the body portionof the blank and may be varied as desired; (3), the relative widths of the web portions of the upper and lower chords at the sides of the slots formed by cutting away of the undesired portions of the web may also be varied as desired; (4), filler pieces ordinarily necessary to build up the web of the end extensions to the required width are eliminated, thereby enabling connection of the web parts of the terminal portions of the upper and lower chords by resistance welding. Thus, V

the invention makes possible an increased output of load bearingmembers of the type described with proportionately reduced costs of production.

The invention is illustrated in the accompanying drawing in which:

Figure 1 ,is a side elevation of one end of a load bearing member constructed in accordance with the invention. l

Figure 2 is a side elevation of the correspondso ing end of a blank from which said memberiis formed. a V l Figure 3 is a similar view ofthe same end of. the blank after spreading of the terminal portions which ultimately are to provide the solid 35 end supportingextension.

Figure 4 is a view similar to Figure 3 showing the arrangement of slits in the web of the blank after the slitting operations.

Figure 5 is a side elevation of the end of the blank after expansion of the trussed body portion of the web and bending of the terminal portion of the lower flange or chord so that a portion of it is co-extensive with and adjacent the terminal portion of the upper chord or flange.

Figure v6 is a side elevational view, somewhat similar to Figure 2, of ablank of slightly different proportions.

Figure '7 is a similar view in which the terminal portions of both the upper and lower chords are 10 deformed to enable slitting of the body portion of the web without slitting of the web portions of the deformed chords. i

Figure 8 is a similar view of the blank after the slitting operation. I 1

Figure 9 is a section taken along line 9-9 of Figure 2. l l

The improved load bearing member which is produced in accordance with the invention comprises an expanded trussed body portion 10 and 110 member may be reinforced by a transversely extending brace 16, the said brace being suitably connected at its ends to the adjacent chords.

The load bearing member is preferably formed from a blank such as illustrated by Figure 2 which in general outline resembles the usual I-beain. First, the web of the blank is cut away at each end to form elongated longitudinally extending openings or slots 17 between the terminal portions 18 and 19 ofthe upper and lower. chords, respectively. The width of each slot is determined by the ultimate width'desired of the web of the supporting extension and may vary from a slit to an extent permitted by the width of the web of the blank, the length of the slot being determined by the width of the blank when expanded and the length of the supporting extension' to be formed, while the relative distances between the margins of. the slot and, the flanges of the adjacent chords are determined by the desired relative strengths of the terminal portions of the respective chords. In other words, the overall dimensions of the slot 17 as well as its arrangement between thechords of the load bearing -memberare variable through a wide range of values, thereby enabling production of load bearing members of the desired characteristics. After the formation of the slot 17, one or both of the terminal portions of the chords may be deformed so as to increase the initial width of the slot l'l-to such an extent that when the blank is passed through the rolls which are adapted to slit the body portion of the web, the slitting ribs of-the rolls will not slit those portions of the web at the sides of .the slots 17. In the embodiment of the invention shown in Figure 3, the increased width of the slot 17 is obtained solely by deformation of the terminal portionl8 of the upper chord, the terminal portion 19 of the lower chord retaining its original form. In this connection it will be understood, of course; that when as in this instance, the terminal portion 19 of the lower chord is not deformed the width of the web portion 20 thereof will be equal to or less than the distance between the lower marginal row of slits, which will be formed in the web during the slitting operation and the adjacent flange. It will be apparent that the extent of deformation of the terminal portion of the upper chord is dependent upon'the initial width of the opening 17 as well as upon the arrangement of the ribs of the slitting rolls which are to perform theslittingoperation.

The blank thus prepared is then passed between the slittingrolls of a stand of the desired construction, during which operation the slitting ribs of the said rolls pass between, and hence out of engagement with, the web portions 20 and 21 of the terminal portions of the lower and upper chords respectively and the body portion of the web isslit in the manner desired. In the embodiment illustrated, marginal rows of slits 22 and an intermediate row of slits 23 are formed, the slits of the marginal rows being in staggered or breakjoint relation to the slits of the intermediate row. The slits of the marginal rows are preferably spaced a greater distance apart than those of the central row and the slitting rolls are operated in such a manner that the angularly extending portion 24 of web of the upper chord escapes the action of the slitting ribs, the first slits in the marginal rows being formed a distance beyond the said portion.

After slitting, the blank may be expanded in any suitable manner, during which operation the upper chord of the load bearing member may be straightened relative to the remainder of the body portion of the said chord. The terminal portion 19 of the lower chord may then be bent in the direction of the terminal portions of the upper chord so that for a portion of its extent the former is co-extensive with and abuts the latter. Ihe

bending of the lower chord in this manner results in its shortening, the terminal portion of the up per chord extending beyond the end of the terminal portion of the lower chord as shown in Figure 5. This may be compensated for, how'- ever, when the ends of the load bearing member are squared off. Either before or after this operation, the co-extensive web portions 20 and 21 of the terminal portions may be suitably united as by welding, thereby providing the load bearing member with end supporting extensions of beam-like form.

It will be apparent that the web of the end supporting extension is made up of the web portions 20 and 21 and inasmuch as the widths of the latter may be as desired, the final width of the web of the end supporting extensions may be selected at will, thereby eliminating the need of filler pieces to enable piecing out of the web to the width desired. The elimination of filler pieces has the advantage that the union of the web portions of theterminal portions of the load bearing member may be convenientlyeffected by r sistance welding. The cross-piece 16 may be employed to reinforce the terminal portions of the load bearing'member, the lower end of said piece preferably abutting the shoulder 25 provided by the slot 17.

In the embodiment just described, the increase in the width of the slot 17 to enable operation of the slitting rolls in the manner required is effected by deflection of the upper chord alone. If desired, however, both upper and lower chords may be operated upon to increase the width of the slot 17. This method of procedure has the advantage that the slot 17 may be formed without regard to the width of the web portion of the terminal portion of the lower chord. Thus, as shown in Figure 6, the web portion 20 may be greater in width than the corresponding web portion of the blank of Figure 2. When this is the case, the width of the slot 17 is increased by defleeting the terminal portions of both the upper and lower chords. After this operation, the blank may be slit, expanded and finished in the manner heretofore described.

From the foregoing it will be apparent that the width of the slot 17 as well as the extent of deflection of the chords may be varied and that'the degree of deflection of the chords is dependent to some extent on the width of the slot. Thus if it is desired that the web of the terminal portions of the load bearing member be substantialy the same width as the original width of the web of the blank the slot 17 is, in fact, a slit and the degree of deflection of the chord, or chords, of the blank must be large enough to permit entry of the ribs of the slitting rolls to the body portion of the blank without engagement of the web portions adjacent the slit.

In addition to increasing the speed of manufacture, the invention has the advantage that the material cut away at each end of the blank is in a single piece, thereby avoiding waste of metal.

I claim as my invention:

1. The method of producing a load bearing member having an expanded body portion and an integral end supporting extension from a blank having a solid web which consists in forming a slot in the web at an end of the blank, the width and length of the said slot being such that the ultimate dimensions of the end supporting extension when formed will be proportioned as required, increasing thewidth of the slot to such an extent as to enable passage of the blank between the rolls which are to slit the body portion of the web without slitting of the web portions at the sides of the slot by separation of the terminal portions of the blank, tlitting the body portion of the web in said rolls, expanding the blank and joining the terminal portions of the chords to form the supporting extension.

2. The method of producing a load bearing member having an expanded body portion and an integral end supporting extension from a blank having a, solid web which consists in forming a slot in the web at one end of the blank, the width and length of said slot being such that the ultimate dimensions of the supporting extension when formed will be proportioned as required, increasing the width of said slot to such an extent as to enable passage of the blank between the rolls which are to slit the body portion of the web without slitting of the web portions at the sides of the slot by bending the terminal portion of one of the chords away from the terminal portion of the companion chord, slitting the body portion of the web in said rolls, expanding the blank and joining the terminal portions of the chords to form the supporting extension.

3. The method of producing a load bearing member having an expanded body portion and an integral end supporting extension from a blank having a solid web which consists in slitting the web at an end of the blank, separating the terminal portions of the blank adjacent the slit to provide for the passage of the rolls which are to slit thebody portion of the blank without slitting of said terminal portions, slitting the body portion of the web, expanding the blank and joining the said terminal portions of the blank to form the supporting extension.

4. The method of producing a load bearing member having an expanded body portion and an integral end supporting extension from a blank having a solid web which consists in forming a slit in the web at an end of the blank, offsetting one of the terminal portions of the slit end of the blank and bending it away from the other to provide a space for the passage of the rolls which are to slit the body portion of the blank without slitting of the said terminal portion, slitting the body portion of the web, expanding the body portion of the web of the blank and bending back the offset terminal portion into the original position it assumed before offsetting, and then joiningthe said terminal portions of the blank to form the supporting extension.

5. The method of producing a load bearing member having an expanded body portion and an integral end supporting extension from a blank having a solid web which consists in forming a slit in the web at an end of the blank, offsetting both of the terminal portions of the slit end of the blank and thereby bending them away from each other to provide a space for the passage of the rolls which are to slit the body portion of the blank without slitting of the said terminal portions, slitting the body portion of the web, expanding the body portion of the web of the blank, bending back one of the offset terminal portions into the original position it assumed before upsetting, and then joining the said terminal portions of the blank to form the supporting exr tension.

6. The method of producing a load bearing member having an expanded body portion and an integral end supporting extension from a blank having flanged top and bottom chord members and a solid web which consists in forming a slot in the web at an end of the blank, the width and length of said slot being such that the ultimate dimensions of the supporting extension 1 when formed will be positioned as required, offsettingboth of the terminal ends of the blank by bending the terminal portions away from each other thereby increasing the width of said slot to such an extent as to enable the passage of the i blank between the rolls which are to slit the body portion of the web without slitting or the web portions at the sides of the slot, slitting the body portion of the web between said rolls, bending back one of the offset terminal portions into the original position it assumed before offsetting, bending the other terminal end portion into aligned engagement therewith, and then joining the two terminal end portions together to form the supporting extension.

HARRY A. KESSLER. 

